1. The problem statement, all variables and given/known data Find the derivative of the function: [itex] f(x)= ∫e^sin(t) dt. [/itex] (A is cos (x) and B is (x^2)) 2. Relevant equations 3. The attempt at a solution I read this site http://mathmistakes.info/facts/CalculusFacts/learn/doi/doi.html and I was wondering how I would be able to determine what problems this technique would work for. It says it has to be an open interval, and the function must be continuous. But in this case, since sin is defined only from -1 to 1, this would not work right? Then what must I do in such a case? Do I take the integral of the function and then plug in the upper and lower limits? I am utterly confused. Thank you.